I'm having trouble finding the right mix of environment vars and MakeMaker/Module::Build directives to build CPAN modules in a specific environment, and I could use some help.

The setup:

1. I am using a compiled-from source perl, configured during the build process to be installed in /tmp/foo/.
2. I have a build script that iterates through a set of CPAN modules in a directory, and builds/installs them in another path (/tmp/cpan) using /tmp/foo/bin/perl in the build process.

This works fine, with CPAN modules using both MakeMaker and Module::Build.

Now the problem:

perl, compiled and installed to /tmp/foo, might get moved to /tmp/bar. No recompilation of perl is possible at this point.

The build script must work now with /tmp/bar/bin/perl to build CPAN modules.

And this is where I'm getting stuck. Pure-perl modules seem to be ok with an updated $PERL5LIB, but modules that require C header files don't want to cooperate. I keep running into problems with modules being unable to find CORE/perl.h.

Adding LIB, PERL_LIB, or PERL_ARCHLIB directives to the call to Makefile.PL doesn't work, and I'm stuck at this point.

Suggestions very much appreciated!